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Патент USA US3094571

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June 18, 1963
Filed Jan. 25, 1960
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Joseph Kern Mer’izweiller
Leroy Virgil Robbins, Jr.
Peter Joseph Berkeley, Jr.
By Ed?’ H ' MPcieni Attorney
United States Patent O??ce
Patented June 18, 1963
found to aid in the decomposition of the oil soluble co
Joseph Kern Mertzweiller and Leroy Virgil Robbins, Jr.,
Baton Rouge, La., and Peter Joseph Berkeley, Jr., Tulsa,
Okla, assignors to Esso Research and Engineering Com
pany, a corporation of Delaware
Filed Jan. 25, 1960, Ser. No. 4,2?6
4 Claims. (Cl. 260-604)
balt carbonyl compounds. However, when such prior
techniques were applied to demetallizing an aldox prod
uct, i.e. a crude aldehyde containing both cobalt and
zinc residues, suf?ciently complete demetallizing has not
been obtained, apparently because the cobalt and zinc
components form a thermally stable complex. More
over, when the cobalt or zinc catalysts or both are added
to the synthesis in the form of water soluble compounds,
e.g. as acetate or sulfate \salts, a very viscous aqueous
solution gradually builds up and reduces the effectiveness
of the synthesis stage. The exact nature of this viscous
lizing aldehydes and alcohols prepared by a process in
material is not completely understood but is believed to
volving in combination carbonylation of an ole?n and
be a supersaturated solution of the zinc salt or other al
aldolization of the resulting aldehyde. More particularly
it relates to an improvement in removing catalyst resi~ 15 dolization catalyst component since the metals such as
zinc do not form oil soluble carbonyls and are therefore
dues, such as cobalt and zinc compounds, from the afore
not sclubilized in the organic synthesis product in the
mentioned aldolized product by steam distillation. Still
This invention relates to an improvement in demetal
more particularly the invention relates to the recovery of
the catalyst in an oil soluble form such that it can be
recycled to the synthesis steps of the process.
An increasingly important commercial process involves
the conversion of lower olefins into aldehydes and alco
hols having more than twice ‘as many carbon atoms as
the original feed.
Essentially this modification of the
well-established oxo process involves reaction of the ole
sense that cobalt is solub‘ilized. If this situation is al
lowed to proceed long enough, the reactor becomes com
pletely ?lled with the viscous product and reaction is
lost. This is particularly aggravated when catalyst is re
cycled from the product demetallizing stage to the syn
thesis stage.
It has now been discovered that all such difficulties can
25 be substantially avoided, and unusually effective removal
?n with carbon monoxide and hydrogen in the presence
of a cobalt carbonylation catalyst at elevated tempera
ture and pressure whereby the ole?n is carbonylated to
of metal-containing catalyst residues from valdox-type
genated to give the corresponding alcohol. Thus, for
ing organic distillation bottoms. These preferably in
clude the dimeric aldoll, i.e. dimenic hydroxy aldehyde,
products can be obtained provided that the crude aldox
product is treated with 1steam under conditions such that
the desired aldehyde and alcohol components are steam
give an aldehyde ‘and an alcohol having one more car
bon atom than the original ole?n. The aldehyde result 30 distilled overhead and no liquid water phase is present
in the demetallizing vessel and provided further that the
ing from this oxo synthesis is then dimerized and dehy
cobalt and aldolization catalysts are originally added to
drated by an aldol reaction in the presence of a dimer
the system in the form of oil soluble compounds such as
ization-dehydration catalyst such as a compound of zinc,
their fatty or naphthenic acid salts. In addition, when
beryllium, magnesium or barium. ‘In this manner alde
operating the steam distillation at or near atmospheric
hydes having twice as many carbon atoms as the inter
pressure, it has been found desirable to maintain the dis
mediate aldehyde are obtained.
tillation temperatures between about ‘200° and 350° F.,
The dehydro-aldolization step can be carried out di
preferably below 300° F., or at correspondingly higher
rectly in the carbonylation stage by including a catalyst
temperatures when operating at more elevated pressures.
such as zinc as well as cobalt in the oxo synthesis mix
ture. Alternatively, the dimerization may be carried out 40 When higher distillation temperatures are employed than
just indicated, increasing amounts of potential dimer al
by subjecting the crude aldehyde eflluent from a con
dehyde product tend to be lost, presumably by reversion
ventional oxo stage to aldolization and dehydration in
of the intermediate dimeric aldol to the monomer alde
the presence of zinc or the like in a separate stage. For
hyde and eventual hydrogenation of the latter.
convenience, both of these alternative oxo-aldol combi
By proceeding in accordance with this invention, the
nation processes will be referred to herein generically as
catalyst residues are recovered from the demetallizing
the “aldox process” or the “aldox synthesis.” -In either
section of the process in oil soluble form in the high boil
case, the resulting dimeric aldox aldehyde can be hydro‘
instance, propylene can be converted to Z-ethylhexenal
and Z-ethylhexanal and eventually to ‘Z-ethylhexanol, bu—
tyraldehyde being the intermediate oxo aldehyde which
is aldolized. Since the crude aldox ‘aldehyde product in
either case contains objectionable cobalt and zinc or
in addition to heavier constituents such as acetals, esters
and other condensation products. The resulting catalyst
containing bottoms can then be advantageously recycled
from the demetallizing section to the aldox section of the
process, thereby providing a major part of the catalyst re
other catalytic metal residues, these must be thoroughly
removed to make the crude aldox aldehyde suitable for 55 quirements of the synthesis stage. In addition, recycling
of the bottoms has been found to increase the yield of
hydrogenation and to assure that the ?nal alcohol prod‘
desired end products.
uct will meet stringent commercial speci?cation-s.
The invention is particularly applicable to the demetal
In the conventional oxo process wherein an ole?n is
lization of aldehydes having 2n+2 carbon atoms obtained
reacted with hydrogen and carbon monoxide in the pres
from ole?ns corresponding to the formula Cnllzn wherein
ence of a cobalt catalyst only, the crude product is nor 60 “n” is an integer ranging from 2 to 5. Suitable ole?ns
mally demetalllized by treatment in the presence of hot
thus include ethylene, propylene, butane-1, butene-2, iso
water. This causes the oil soluble cobalt carbonyl com
butylene, as well as any pentene isomers which on oxona
pounds to decompose, usually in the form of a precipi
tion produce an aldehyde having at least one hydrogen
tate. See US. Patents 2,679,534 and ‘2,779,794. In the 65 atom on the carbon atom adjacent to the aldehyde group,
conventional oxo synthesis it has also been known to
i.e. the ole?n must lead to an aldehyde capable of aldoliza
decobalt crude, water-containing aldehyde product by
steam distillation and to recycle the resulting catalyst
The aforementioned ole?n feed is reacted with a syn
containing aqueous distillation bottoms to the synthesis.
thesis gas mixture containing hydrogen and carbon monox
See US. Patent 2,564,130. Each of these prior processes 70 ide in a ratio between about 0.25 to 4 volumes of hydro
gen per volume of carbon monoxide, HZ/CO volume
has been characterized by the presence of a liquid water
phase in the decobalting vessel since the water has been
ratios between 1/1 and 2/1 being prefenred. The opti
mum conditions for reacting the ole?n with the synthesis
gas varies somewhat depending on the nature of the
ole?n ‘feed, but generally the reaction is conducted at
pressures of about 1500 to 4500 p.s.i.g., preferably 2500
to 3500 p.s.i.g., and at temperatures in the range of from
about 200° to 450° F., preferably 250° to 375° F. About
2500 to 25,000 cubic feet of hydrogen and carbon monox
CHa.CH2.CHz.CHz.CH.CHO + H2 —-—>
ide (measured at standard temperature and pressure),
preferably 4,000 to 6,000 standard cubic feet, per barrel
of liquid ole?n feed are normally ‘employed.
Both the one-step process and the two-step process
In the one-step “aldox” process the catalyst for this
result in a crude aldehyde mixture, hereinafter referred
reaction is a mixture of cobalt and zinc compounds sup
plied in a water insoluble form, e.g., in the form of metal
powder or turnings or in the form of metal salts of C6 to
C18 and higher fatty acids, such as hexanoic, lauric, ste
aric, oleic, linoleic, or other suitable organic acids such
as naphthenic. In this manner cobalt is generally added
to the extent of 0.2 to. 0.5% calculated as metal on ole?n
to as the “crude aldox mixture,” which contains as prin
cipal products the unsaturated and saturated dimer alde
hydes corresponding to reactionsv 3 and 4 described above,
as well as varying amounts of the monomer aldehyde
from reaction 1, its dimeric aldol from reaction 2, the
corresponding alcohols, heavy condensation products and
the metal-containing catalyst residues. This crude aldox
feed, while zinc is ‘added to the extent of 0.05 to 0.5 %,
mixture must then be effectively demetallized before the
preferably 0.1 to 0.2% calculated as metal on ole?n feed. 20 aldehydes contained therein are hydrogenated to produce
The crude liquid aldehyde product from this synthesis
high-quality alcohols suitable for the manufacture of
plasticizers and the like. It is with this demetallizing step
and alcohols as well as the catalyst, substantially as de
that the present invention is concerned.
scribed in US. Patent 2,811,567 to which reference may
The present invention and its application will best be
be had for further details.
25 understood from the following more detailed description,
Alternatively, instead of converting the ole?n to the
wherein reference will be had to the accompanying draw
dimer aldehyde in one step by the so-called aldox reaction
ing. This drawing is a schematic representation of a sys
contains a mixture of both monomer and dimer aldehydes
just described, the present invention is similarly applicable
tem suitable for carrying out 1a preferred embodiment of
to dimer aldehydes obtained by the two-step process
the invention.
wherein the crude aldehyde obtained in a conventional 30
Referring now to the drawing, propylene is fed through
oxo synthesis is aldolized and dehydrated in the presence
of zinc or other aldolization-dehydration catalyzing metals
or their water-insoluble compounds as hereinbefore de
feed line 1 to the bottom of primary reactor 10.
latter comprises a reaction vessel preferably divided into
a plurality of discrete zones separated by trays and a free
scribed. In such a process the cobalt catalyst used in the
space. The reactor is desirably packed with inert solids
oxo step is usually allowed to remain in the oxo aldehyde 35 to facilitate gas-liquid contact.
being passed to the aldolization stage so that the crude
Also passed into reactor 10 are a cobalt carbonylation
aldox aldehyde product normally contains both the oxo
catalyst, e.g. cobalt oleate, and a dimerizationdehydration
catalyst and the aldolization catalyst. The general opera—
catalyst, e.g. zinc oleate. These water-insoluble catalysts
'tion of such a process is described in US. Patent 2,820,
may be added as solutions in the ole?nic feed or in the
067 to which reference may be had for further details. 40 oily distillation residue obtained from demetallizer 40
The oxo step ‘of the twoestep process is carried out under
as hereafter described. In a preferred embodiment a
substantially the same conditions as those described here
solution of cobalt oleate in propylene is added to the
inbefore with reference to the one-step aldox synthesis
bottom of reactor 10 via line 2, while zinc oleate may
except that, due to‘ the absence of zinc in the conventional
be added to an intermediate zone of reactor 10 via line 3
oxo step, the cobalt concentration in the latter may be re
after dissolving the zinc soap in the recycled distillation
duced to 0.1 percent or even less, based on the ole?n feed. 45 residue passing from demetallizer 40 to reactor 10. . It
Taking the manufacture of 2-ethylhexanol from propyl
ene as an example, it will be understood that both the
one-step process and the two-step process involve the fol
lowing combination or sequence of reactions:
03115 + CO + H5 -_> CH3.CH2.CH2.CHO
catalysts may be added in the ole?n feed to the bottom
of the reactor instead of adding each catalyst component
50 separately as hereinbefore indicated. Also, since the
present invention permits recycling the required catalysts
from the demetallizing stage to the primary reaction stage
or stages, once the process has achieved a steady state
2(CH;.CH2.CH1.J7O) <—_> CH;.GH2.OH;.OH.GH.OHO
will be understood, however, that at least when the process
is ?rst put on stream, a mixture of cobalt and zinc
the respective catalyst components need to be added only
in amounts suf?cient to compensate for any catalyst lost
or purged from the process. Furthermore, while the
catalysts may originally be added in the form of oil
soluble soaps or in the metallic form, it is ‘known that
the cobalt catalyst in particular will be changed in the
60 process to a cobalt carbonyl compound. In the preferred
embodiment the cobalt oleate is fed to reactor 10 in an
amount of about 0.2 to 0.5%, e.g. 0.3%, while zinc
OH3.0H2.0H3.CHICH.OHO + H10
'onaontontcmoncno + H, ——t
I Hz '
oleate is added in an amount of about 0.1 to 0.2%, e.g.
0.15% each calculated as metal based on ole?n being
65 fed to reactor 10.
Simultaneously a gas mixture containing H2 and CO
in approximately equimolar ratio is supplied through
line 5 and ?ows concurrently with the propylene and the
resulting aldehyde product upwardly through the reactor.
70 The latter is preferably operated at pressures of 2500 to
3500 p.s.i.g., e.g. 3000 p.s.i.g., and temperatures of about
200° to 400° F., e.g. 350° F.
Liquid oxygenated reaction product or crude aldox
mixture comprising aldehydes is Withdrawn from an
upper portion of the reactor through line 6. The product
is then preferably cooled in heat exchanger 7 to a tem
perature of about 60° to 150° F. and then passed to a
high pressure gas-liquid separator 20. Here separation
of unreacted gases from liquid product occurs. The un
reacted gases may be withdrawn through line 21 and
recycled through line 5 to the system or purged as
desired. The remaining crude aldox mixture containing
in solution essentially all of the initially added cobalt
hyde or aldol is Withdrawn as part of the bottoms rather
than as part of the distillate product, it has been found
that an important increase in the yield of the desired
?nal C8 alcohol product can be obtained since otherwise
the inclusion of the aldol in the distillate has been found
to lead to a partial reversion of the C8 aldol to butyralde
hyde in subsequent processing steps. However, demetal
lizing in accordance with this invention is effective even
when the aldol is distilled overhead.
and zinc catalyst is withdrawn from high pressure sepa
rator 20 through line 22, expanded through pressure 10 The distillate withdrawn via line 45 is condensed in
cooler ‘49 and passed to product receiver 50. Here the
release valve 23 and introduced into low pressure sepa
condensate separates to vform a water layer which may
rator 30. The released gas may be purged via line 31,
contain’ signi?cant amounts of C4 aldehyde and alcohol,
all in accordance with well-known prior practice.
an oily crude aldehyde product layer, and gas which may
After this step the liquid material is sent via line 32
to demetallizer vessel 40 wherein the essential feature of H 01 be vented via‘ line ‘51. The demetallized, catalyst-free
crude ‘aldehyde product is withdrawn from receiver 50
the invention is performed. The demetallizer of the
via line 52 and, preferably after fractional distillation
present invention is a distillation column which may
to separate the monomeric C4 aldehyde from the dimeric
contain from 1 to 10 stages, e.g. three plates. The column
C8 valde'hydes, the latter are converted‘ to the desired
is desirably operated at substantially atmospheric pressure
Z-ethylhexanol by hydrogenation in :an otherwise well
through moderately super-atmospheric pressure, e.g. up
known manner not illustrated in the drawing. The water
to 50 p.s.i.a., or moderately sub-atmospheric pressure,
layer is withdrawn from receiver 50 via line '54, partially
egg. 2 p.s.i.a., are also operable. Steam is introduced into
vaporized in vaporizer 55 and the resulting steam and
the demetallizer via line 41 at a ratio between about
vaporized C4 products returned to demetallizer 40 via line
one and four parts of steam per part of crude aldox mix
ture introduced via line 32. When operating at about 25 41 as previously described. A portion of [the water may
be purged via line 56 to reduce scale formation. Any
atmospheric pressure, the bottom temperature of the
small amounts of catalytic metals contained in this purge
vessel is maintained in the range between about 215°
stream may be recovered therefrom if desired, e.g. by con
and 275° F., preferably at about 260° F. in the case
tact with \a cation’ exchange resin.
of C3 aldehydes. In any event it is essential to main
it will be understood that while the invention was de
tain conditions in tower 40 such that no liquid water
scribed with particular reference to an aldox process
phase forms therein. In addition, the temperatures in
wherein an ole?n is converted to the corresponding dimer
this tower must be above the normal decomposition of
aldehyde in a single vessel containing several distinct
cobalt carbonyl and hydrocarbonyl compounds, i.e. above
stages, the invention is similarly applicable both to aldox
125° F., but below temperatures that would cause decom
position of the cobalt compounds into solid oil-insoluble 35 processes containing only ‘a single principal reaction stage
and to processes wherein the e?'iuent from a conventional
precipitates. Also as pointed out earlier herein, the tem
cobalt catalyzed oxo stage [is converted to the correspond
perature is preferably low enough to prevent much of the
ing dimer aldehyde in the presence of added zinc in a
dimeric aldol from leaving the demetallizer overhead.
separate aldolization-dehydration reactor. Of course, the
Where the heat content of the introduced steam via line
synthesis conditions will have some effect on the particu
41 is insuf?cient to assure absence of liquid water in the
lar composition of the distillation residue Withdrawn from
demetallizing vessel 40, additional heat may be supplied
thereto by means of a steam coil 42 or by other appro
priate means. Of course, the steam introduced into the
the steam distillation tower 140‘.
In any event, however,
the invention is characterized by retaining in the steam
distillation demetallizer an organic residue boiling higher
vessel directly via line 411 may be superheated to appro
than the desired dimer alcohol (e.g. Z-ethylhexanol when
priate temperatures such as 350° F., i.e. l25-pounds
propylene feed is used. This residue will contain much of
steam may be used.
the catalyst present in the crude aldox product mixture
An overhead product consisting essentially of C8 alde
while the distillate will be substantially free of metal.
hydes (RP. about 345° F.), some 2-ethylhexanol (B.P.
Since all or nearly all the catalyst is present in the Oily
362° F.) plus butyraldehyde and butyl alcohol are with
drawn overhead via line 415. A distillation residue pref 50 residue in dissolved ‘form, recycling of this residue to the
reactor provides an unusually effective utilization of the
erably containing the C8 aldol (hydroxy aldehyde; B.P.
384° F.) and all heavier by-products such as acetals and
esters as well as the catalyst are withdrawn from the
bottom of the demetallizer via line 46, cooled to about
operation carried out in ac
60° to 120° F., e.g. 100° F., in heat exchanger 47 and
cordance with the present invention the following data
returned to reactor 10 via line 4. In this manner a high
were obtained:
degree of catalyst utilization is effected and an increased
product yield obtained. When the zinc aldolization
Composition 0]‘ Feed to Demeta'llizer
dehydration step is carried out subsequent to a conven
Crude Aldox Mixture:
tional oxo stage, it is preferable to recycle at least a 60
major part of the aldol-containing distillation residue
directly to the aldolization step. ‘However, this requires
supplying an appropriately greater makeup amount of
i-Butyraldehyde ________________________ __
n~Butyraldehyde _______________________ __
_____________________________ __
fresh cobalt catalyst to the oxo stage and the purging of
C8 aldehyde ___________________________ __ 28.6
a corresponding amount of the catalyst recycle, e.g. via 65
C8 alcohols
line 48. The distillation residue withdrawn via line 46
Bottoms ______________________________ .. 25.0
may amount to about 0.5 to 15%, preferably about 1 to
Unknown _____________________________ __
5%, e.g. 2%, of the crude aldox mixture introduced into
the distillation tower via line 32. ‘The optimum amount
withdrawn as bottoms depends of course on speci?c syn 70
thesis conditions and consequent composition of the
product. Cooling of the distillation residue prior to
Cobalt _____________________________ .. 0.1010
reintroduction into the exothermic reactor 10 accomplishes
the necessary cooling. In addition, by operating tower
49 so that the relatively high boiling C8 hydroxy alde 75
_______________________________ __ 0.1870
This crude ialdox mixture was subjected to steam dis
till-ration in a recti?cation column (2 inches diameter, 2
feet long) packed with Raschig rings. The column was
operated at a steam oil ratio of 2.0, at atmospheric pres
sure and 1a temperature of 258° IF. (average temperature
at middle of column).
genated product having not more than 2n+2 carbon
atoms per molecule, separating an organic phase com
prising an aldehyde having 2n+2 carbon atoms from
the said distillate and withdrawing from said distillation
Composition of E?‘luent Streams From Demetallizer
Bottoms (1.7% on demetallized \aldox product):
C0, percent
zone a catalyst-containing bottoms fraction.
2. A process according to claim 1 wherein the catalyst
containing bottoms fraction withdrawn from the steam
____ 0.77
Zn, percent ____________________________ __ 1.26
AldoX .‘Product, Composition:
Zone, removing from said distillation zone as a distillate
a mixture of steam and substantially catalyst-free oxy
distillation zone amounts to about 0.5 to 15% based on
the crude dimer aldehyde introduced into the distillation
i-Butyraldehyde ________________________ __ 13.8
n-Butyraldehyde _______________________ __ 19.9
zone and is recycled to the dimer aldehyde synthesis zone.
3. In a carbonylation process wherein propylene is ox
onated with carbon monoxide and hydrogen in the pres
ence of a water-insoluble, oil-soluble cobalt carbonylation
n-‘Butanol _____________________________ __
catalyst to produce ‘a C4 aldehyde :and the resulting C4
C8 aldehyde ___________________________ __ 34.4
C8 alcohol ____________________________ __ 2.1
hyde and containing cobalt and zinc compounds, the
improvement which comprises introducing the said crude
_ 22.9
Unknown ________ _; ___________________ __
Metal Content:
aldehyde is dimerized and dehydrated in a reaction zone
in the presence of a water-insoluble oil-soluble zinc com
pound to produce a crude aldox mixture rich in C8 alde
C8 'aldox mixture into a distillation zone, introducing
steam into said mixture and maintaining it at a tempera
percent _________________________ .._
ture between about 212° and 275° F. and under a pres—
Water Layer:
sure such that no liquid water phase exists in said distilla~
Oil content, percent __________________ __
00, percent
tion zone, withdrawing as a distillate from said distilla
tion zone a demetallized mixture comprising C8 aldehydes
and steam, separating from said distillate an organic
product rich in C8 aldehyde, withdrawing from said dis
Substantially complete demetallization of the product
tillation zone ‘a bottoms fraction containing C8 aldol and
higher boiling oxygenated products as well as oil-soluble
has thus been ‘achieved ‘While about 70% of the catalyst
fed to the process has thus been recovered in the bottoms
cobalt and zinc compounds, cooling the withdrawn bot
in a form suitable for recycling. The remainder of the
catalyst plated out on various vessels and lines. The
data further show that the demetallized process of this
invention had a very desirable e?ect on the composition
toms fraction and recycling it to the said reaction zone.
4. In a carbonylation process wherein propylene is re
acted with carbon monoxide and hydrogen in the presence
'of a water-insoluble oil-soluble cobalt carbonylation cat
alyst in a ?rst stage under conditions to produce a mix
ture rich in butyraldehyde and the resulting reaction
Unless otherwise indicated, all percentages and pro
portions of materials are expressed herein on a weight 40 mixture is heat soaked in a second stage in the presence
of a water-insoluble oil-soluble zinc catalyst added thereto
‘of the product mixture in that the concentration of the C8
aldehyde has been increased.
Since many different ways of practicing the invention
will [occur to those skilled in the alt, it will be understood
that the scope of the invention described herein is not to
be limited except as set ‘forth in the following claims.
to produce a crude product rich in C8 aldehyde, the im
provement which comprises introducing steam into said
crude product in a distillation zone 3J1 a temperature be
tween about 212° and 275 ° F. and under a pressure such
that no liquid water exists in said distillation zone, with
drawing from said distillation zone an overhead stream
1. In a carbonyl‘ation process wherein a monoole?n
containing demetallized C8 aldehyde, withdrawing from
containing n carbon atoms, n being an integer ranging
said distillation zone a bottoms fraction amounting to
from 2 to 5, is contacted with carbon monoxide and hy
drogen in the presence of a water-insoluble, oil-soluble 50 about 1 to 5% based on said crude product and con
taining oil-soluble catalyst compounds dissolved therein,
We claim:
cobalt carbonylation catalyst under conditions to produce
recycling the said bottoms fraction directly to said zinc
an aldehyde containing n+1 carbon atoms and the alde
,containing second stage, and adding fresh oil-soluble co
hyde is contacted with a wateninsoluble, oil-soluble di
balt carbonylation catalyst to said ?rst stage.
merization-dehydration catalyst in a synthesis zone under
‘conditions to produce a crude dimer aldehyde containing 55
References Cited in the ?le of this patent
2n—|—2 carbon atoms and containing catalyst residues dis
solved therein, the improvement which comprises steam
distilling in a distillation zone the catalyst-containing crude
dimer aldehyde at a temperature between about 212°
and 275° F. under conditions such that substantially no 60
liquid water phase is ‘maintained in said steam distillation
Gwynn ______________ __ June 14,
Gwynn et al. ________ __ May 29,
Munger ______________ __ Jan. 29,
Mertzweiller et al. ____ __ Jan. 14,
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